Q-201. LAS-Response of Bacteria Isolated from Sediments of Some Detergent-Effluent Polluted Water Bodies in Ilorin, Nigeria

T. M. Kayode-Isola1, E. T. I. Kehinde2, A. B. Olayemi2, S. Awe2;
1Adeniran Ogunsanya Coll. of Ed., Lagos, NIGERIA, 2Environmental and Pub. Hlth. Res. (EPHR) Lab., Univ. of Ilorin, Ilorin, NIGERIA.

The effect of concentration of linear alkylbenzene sulfonate (LAS) in sediments of some tropical water bodies on the population of bacteria in the sediments was studied. The bacteria isolated from the sediments were tested for tolerance to different concentrations of LAS using media dilution technique. LAS-tolerance was indicated by growth of the bacteria in the presence of the surfactant. The sediments were alkaline (pH 8.2 to 12.0) with high surfactant concentration (45 to 132mg/g). A direct relationship existed between the pH and the concentration of surfactant in the sediment (r= 0.9124). The sediments haboured a high population and variety of bacteria; viable heterotrophic bacteria population ranged between 2.9× 105 and 1.2× 107 cfu/g and populations of LAS-tolerant bacteria (LTB) ranged between 1.5× 104 and 1.2× 106 cfu/g. A direct relation existed between the populations of heterotrophic bacteria and LTB (r=0.9500). Population of heterotrophic bacteria (r= -0.9303) and LTB (-0.9143) varied inversely with the concentration of surfactant. Twelve bacteria: Alcaligenes odorans, Bacillus subtilis, Burkholderia cepacia Citrobacter freundii, Escherichia coli, Micrococcus luteus M. albus, Proteus vulgaris, Pseudomonas putida, Ps. stutzeri, Staphylococcus aureus, and Streptococcus bovis were isolated. The bacteria varied in their tolerance of LAS; with the maximum toleratable concentrations ranging from 0.03 to >1.0g/l. The sediment can be a potential source of adapted organisms which can be used in biotreatment of LAS-bearing waste.